Today it is wildly recognized that optimization based on rewriting leads to faster query execution. The role of a query rewriting grows significantly when a query defined in terms of some view is processed. Using views is a good idea for building flexible virtual data integration systems with declarative query support. At present time such systems tend to be based on the XML data model and use ...

We deene a variant LKsp of the Gentzen sequent calculus LK. In LKsp weakenings or contractions can be done in parallel. This modiication allows us to interpret a symmetrical system of mix elimination rules ELKsp by a nite rewriting system; the termination of this rewriting system can be checked by machines. We give also a self-contained strong normalisation proof by structural induction. We giv...

Categorical Multi Combinators form a rewriting system developed with the aim of providing e cient implementations of lazy functional languages The core of the system of Categorical Multi Combinators consists of only four rewriting laws with a very low pattern matching complexity This system allows the equivalent of several reductions to be performed at once as functions form frames with all the...

We present new techniques to prove termination of cycle rewriting, that is, string rewriting on cycles, which are strings in which the start and end are connected. Our main technique is to transform cycle rewriting into string rewriting and then apply state of the art techniques to prove termination of the string rewrite system. We present three such transformations, and prove for all of them t...

Sesqui-pushout (sqpo) rewriting—“sesqui” means “one and a half” in Latin—is a new algebraic approach to abstract rewriting in any category. sqpo rewriting is a deterministic and conservative extension of double-pushout (dpo) rewriting, which allows to model “deletion in unknown context”, a typical feature of single-pushout (spo) rewriting, as well as cloning. After illustrating the expressivene...

Sesqui-pushout (sqpo) rewriting—“sesqui” means “one and a half” in Latin—is a new algebraic approach to abstract rewriting in any category. sqpo rewriting is a deterministic and conservative extension of double-pushout (dpo) rewriting, which allows to model “deletion in unknown context”, a typical feature of single-pushout (spo) rewriting, as well as cloning. After illustrating the expressivene...

We present extended term rewriting systems as a means to describe a simpliication relation for an equational speciication with a built-in domain of external objects. Even if the extended term rewriting system is canonical, the combined relation including built-in computations of`ground terms' needs neither be terminating nor connuent. We investigate restrictions on the extended term rewriting s...

We present new techniques to prove termination of cycle rewriting, that is, string rewriting on cycles, which are strings in which the start and end are connected. Our main technique is to transform cycle rewriting into string rewriting and then apply state of the art techniques to prove termination of the string rewrite system. We present three such transformations, and prove for all of them t...

Grew: a Graph Rewriting Tool for NLP We present a Graph Rewriting Tool dedicated to NLP applications. Graph nodes contain feature structures and edges describe relations between nodes. We explain the Graph Rewriting framework we use, the implemented system and some experiments. MOTS-CLÉS : réécriture de graphes, interface syntaxe-sémantique.

We deene an equivalent variant LK sp of the Gentzen sequent calculus LK. In LK sp weakenings or contractions can be performed in parallel. This modiication allows us to interpret a symmetrical system of mix elimination rules E LKsp by a nite rewriting system; the termination of this rewriting system can be machine checked. We give also a self-contained strong normalization proof by structural i...